I have 1 of the earlier N scale bachmann 2-6-6-2's, on level track it will pull about 25 atlas 33' coal cars, I have a 3% grade going east bound and 4% going west bound and I,m lucky if the loco will pull more then 5 cars up either grade. In the May 2009 Model Railroader mag on page 82 there is a product called Bullfrog Snot Traction-tire maker that allows you to make your own traction tires. As far as sound is concerned Bachmann will probably just equipe the loco  with non sound Dcc. I installed a Soundtraxx micro-tsunami medium steam sound decoder in the tender and had enough room in the tender to use a .62 round speaker and still have enough room to also install the capacitor supplied with the decoder.  Ron